I argue that your email address for registrars should be secret[1], and every time an email goes to it an alarm bell should ring until someone reads it. [1] So

I argue that your email address for registrars should be secret[1], and every time an email goes to it an alarm bell should ring until someone reads it. [1] So don't use "domain@mycompany.com", use "domain-manager-481234@mycompany.com". Recognize that this is purely an obfuscation layer, not meant to provide security in and of itself, but to cut down on the noise so that you always examine every mail to it very closely.